Tracking task. A) Participants were seated before a computer monitor and griped one (tracking task) or both (limb position matching task) horizontally mounted levers. Draping is drawn over the shoulders to prevent visualization of arm movement, represented by a dashed line in B. C) All participants tracked a target following movement patterns similar to these two example trials. Following a 3s stable baseline, a sine-cosine waveforms dictated target movement in degrees up or down at the horizontal center of the screen. Two full trial waveform patterns, each consisting of 1 random and 1 repeated segment, are overlaid in the diagram to demonstrate that all trials had an identical segment common to each. The random segment comes first, followed by the repeated segment during both trials for ease of visualization.